1. Field of the Invention
The present invention relates to a cantilever sensor and a fabrication method thereof.
2. Description of the Prior Art
Recently, since a miniaturized sensor fabricated by MEMS (micro electronic mechanical system) process has quick response and high sensitivity and is appropriate to mass production, it has become the object of interest.
By applying semiconductor minute process techniques where processes such as deposition and etching are performed repeatedly, the MEMS process enables a mass-production of low-cost micro products which has lower power consumption and more accurate operation in comparison with the existing bulk type products. Accordingly, importance of the MEMS process is growing greater day by day with the advent of nano-techniques and SOC (system on chip) techniques.
In order to sense physical phenomenon or chemical reaction, researches into a cantilever sensor fabricated by the MEMS process are actively going on.
Most of the conventional cantilever sensors perform measurement by sensing resonance frequency variation or static deflection due to heat or mass variation using a light source such as laser. However, in the conventional sensor using a light source such as laser, there is a limit to reduce a size of the sensor because of the light source and optical system installation.
FIG. 1 illustrates the conventional cantilever sensor using a light source. When an operating portion 11 of the cantilever sensor senses resonance frequency variation or static deflection due to heat or mass variation of a sensing material 12, laser light is focused by a light source 13 and a sensing signal from the operating portion 11 is detected by a position sensing diode 14.
Since the conventional sensor includes the light source 13 for measuring a signal generated from the operating portion 11; and the position sensing diode 14 for collecting light as a detector, it is difficult to reduce a size of a sensing system.
In addition, in order to sense biomass such as DNA or protein, several gold patterns are formed as an array pattern onto a substrate such as glass, silicon wafer, etc. so as to form a bio recognition organic molecular film thereon, and accordingly a surface modification process is performed. When an object sensing biomass as a probe is combined with an analyte material, fluorescent light is generated by a labeled dye material in irradiation of laser, etc., and the fluorescent is sensed by a light sensing detector (or scanner). However, since the system also needs a light source and a detector as well as an optical system for focusing light, it is difficult to minimize the system.